Robotic mobility rehabilitation system using virtual reality

The application of robotic technology and virtual reality in rehabilitation is an emerging research field. The motivation behind the research efforts is the large patient populations in need of better rehabilitation therapy at lower costs. Walking impairments pose serious problems to the disabled when clearing a curb, walking on an uneven sidewalk surface, or crossing a street.; A common feature of the existing gait rehabilitation systems is the treadmill, which provides the patient with means to exercise walking on a smooth and continuous surface. However, in real life, the patient needs to negotiate uneven surfaces with various properties. The main subject of this thesis is the development of a walking simulator that can render a larger variety of walking surfaces. The simulator uses two compact Stewart platform robots attached to the patient's feet. The servo loop software controls simultaneously the positions and forces of each robot. The two robots simulate the functioning of a treadmill by moving one foot backward while the patient moves the other one forward. Using the 6DOF provided by each Stewart platform, the system can render uneven walking surfaces, and various surface conditions such as mud, ice, or gravel. A VR simulation of crossing a street has been developed and integrated with the simulator. The virtual environment supports several configurations to adjust the exercise difficulty to the patient's abilities, as well as provide him with a realistic exercising environment. The simulation configurable variables include shape and height of the sidewalk edge, street surface condition, scene visibility, and vehicle behavior. The sensor readings output by the controller during the therapy are stored on the PC running the VR simulation and transmitted to an Oracle database for later remote consultation and evaluation.; The simulator is part of a distributed virtual reality rehabilitation framework. Several prototype rehabilitation systems using robotics and VR have been integrated in a common framework that supports telerehabilitation and telemonitoring. The framework consists of a network of servers. It provides the remote therapist with a simplified version of the VR exercise executed by the patient. The VR applications displayed to the patient and therapist are synchronized in real-time over the network. The therapist controls the parameters of the patient's exercise; through the interface provided by the simplified VR simulation. The rehabilitation framework also provides the integrated systems with a unified approach to data storage in an Oracle database. A web portal for the mobility simulator is currently under development to allow the therapist to evaluate the patient's progress using the clinical data collected during therapy.